I understand what you are saying, BUT if the detective didnt know what was going on and a well packed snowball hit his hummer... maybe he thought someone was shooting or something and that was his first reaction. from the looks of it he didnt just get out of the vehicle see a bunch of kids throwing snowballs and start waving the gun around... I think the old man was startled and didnt know what was going on, he was just doing his job. I mean watch the guys reaction when he gets around the front of the vehicle, he almost looks relieved and starts to put the gun away.